Answer:
B
Step-by-step explanation:
given
- 4x²(3x - 7)
multiply each term in the parenthesis by - 4x²
= (-4x² × 3x) + ( - 4x² × - 7)
= - 12x³ + 28x² → B
Answer:
Every week, the radioactivity decreases by a factor of 5
After 1 week, it goes from 5,000 to 1,000
2 weeks 1,000 / 5 =200
3 weeks 200 / 5 = 40
4 weeks 40 / 5 = 8
5 weeks 8 / 5 = 1.6
6 weeks 1.6 / 5 = 0.064
7 weeks 0.064 / 5 = 0.0128
8 weeks .0128 / 5 = 0.00256
9 weeks 0.00256 / 5 = 0.000512
10 weeks 0.000512 / 5 = 0.0001024
Step-by-step explanation:
Isolate one term (x or y) in one of the equations
6x+6y=0
6x=-6y
X= -1y
Substitute x=-y into the other equation
-7(-y) + 2y =18
7y + 2y =18
9y=18
Y=2
Substitute y=2 into 6x+6y=0
6x + 6(2) = 0
6x + 12=0
6x= -12
X = -2
Answer:
I owed a friend 15 bucks till someone payed for me 2/3 of what I owed so I only had to pay him back 5 bucks.